The present invention relates to apparatuses and methods for injecting fluid into a patient, and, more particularly, to apparatuses and methods for injecting fluid into a patient in which syringe information relevant to the injection procedure is encoded and shared with an injector.
The parameters of an injection procedure, such as the injection of contrast agents into a patient, include, for example, fluid volume available for delivery, flow rate, fluid pressure, and limits of piston travel. Injection parameters are determined by several variables, including, for example, syringe diameter, syringe length and fluid composition.
To program an injection procedure, some or all of the above injection parameters and variables, for example, must be input into the injector. In current injector systems, syringe size is input into an injector either (1) manually by an operator who enters the syringe size or syringe type into the injector software, or (2) automatically by means of switches on the injector head which are mechanically coupled to raised or sunken elements on the syringe barrel. Constraints on mechanical and electrical design, however, limit the number of such automatic detection switches. Indeed, only limited syringe configurations are automatically detected with present systems. (As used herein, the terms xe2x80x9csyringe configurationxe2x80x9d or xe2x80x9csyringe informationxe2x80x9d encompasses all information about a particular syringe, including, but not limited to, information about the mechanical properties of a syringe (for example, length, diameter, available volume, pressure limitations, expiration date, prior use, and manufacturer) as well as information about the contents of the syringe (for example, fluid volume, expiration date, manufacturer and composition).
With the increasing variety of syringes and fluids contained therein, and especially prefilled syringes, a greater amount of syringe configuration information must be input into and accepted by injectors to program and control injection procedures. By providing an injector system having the capability to automatically obtain syringe configuration information from syringes with minimal or no operator intervention, injection procedures can be efficiently programmed and controlled, and/or recorded for billing or other purposes.
The present invention provides generally apparatuses and methods for sharing information on syringe configuration between syringes and injector systems. The syringe configuration information carried by syringes or other elements can be automatically accessed by or input into injectors to program and/or control injection procedures, such as angiographic, CT, MR and ultrasound injection procedures.
Further, the present invention may be used to generate and maintain data records associated with injection procedures. For example, to update inventory control records and to satisfy medical and insurance billing and cost information requirements, records of information, such as the type of syringe used, the amount of contrast medium used, the type of contrast medium used, the sterilization date, the expiration date, lot codes, the properties of the contrast media, and/or other clinically relevant information, may be generated and maintained for use by, for example, external billing, inventory or control computer systems.
The present invention provides a syringe for use with a powered injector including a drive member and a having a detector or detection circuit in communication therewith. The detector may be incorporated within the injector. The syringe preferably comprises an elongated body and a plunger slidably disposed within the elongated body and operable to be driven by the drive member. The syringe also preferably comprises a means or mechanism adapted to convey syringe information to the detector or detection circuit.
The mechanism adapted to convey syringe information to the detection circuit may be included in an encoded element (for example, a cap that fits over the syringe plunger or a fluid path element that is connected to the syringe) that includes a store of syringe information and is separate from and connectable to the syringe. Alternatively, the attachable element incorporating the syringe information may be connectable or attachable to the injector or the detector.
In general, syringe information can be conveyed using various energy sources including, for example, electrical, magnetic, radio frequency, optical and ultrasound. Physical indicia can also be used. Combinations of one or more energy sources and/or physical indicia are also possible.
In the case that the information is encoded directly upon the syringe, areas of intimate contact between the syringe and another element are preferably used to convey the information. Because intimate contact is made between the plunger and the drive member, for example, the plunger/drive member interface provides a good place to transmit information regarding syringe configuration to the detection circuit. The present invention thus provides a syringe as described above in which the plunger includes information regarding the syringe encoded thereon. This information may be conveyed to the detector of the injector via one or more readout members or sensors in the drive member of the injector.
In the case of a number of syringes, a pressure jacket (typically, a robust cylindrical element) enables a relatively thin-walled syringe to be used at high pressures. In one embodiment of the present invention, information stored on the syringe (preferably, on the elongated body or barrel of the syringe) is communicated from the syringe to the pressure jacket.
Also, heaters are sometimes used to heat the contents of a syringe to, for example, body temperature (see, for example, U.S. Pat. No. 4,006,736). The interface between the syringe and such a heater also provides a useful interface for transfer of information.
In the case the information is encoded directly upon the syringe or upon an encoded element attached to or connected to the syringe, the syringe may comprise alignment elements that cooperate with associated alignment elements upon an injector, a pressure jacket or a heater element to align encoded elements on the syringe with cooperating readout elements of the detector.
According to one aspect of the present invention, a system is provided comprising a syringe for use with a powered injector to inject a fluid into a patient. The syringe includes an elongated body and a plunger slidably disposed therein as described above. The powered injector includes a drive member and is in communication with a detector or a detection circuit. The detector is communicative connection with or comprises at least one electrically conductive readout contact member.
The system further includes at least one electrically conductive code contact member adapted to contact and make an electrical connection with the readout contact member(s). The code contact member or members encode or are in communicative connection with encoded information relevant to the syringe configuration to transmit such encoded information to be read by the detection circuit when the code contact member(s) are in electrical connection with the readout contact member(s).
Preferably, the system comprises a plurality of electrically conductive code contact members. Each of the plurality of code contact members may be positioned to contact and make an electrical connection with only one of a plurality of electrically conductive readout contact members.
In one embodiment, the conductive code contact members are brought to a state of either digital high or digital low upon contact with corresponding readout contact members of the powered injector when the syringe and the powered injector are in operative connection. Preferably, one of the readout contact members is maintained at digital ground and the remainder of the readout contact members are maintained at a non-zero potential. Any code contact member in electrical connection with the digital ground readout contact member is preferably interpreted as being in a state of digital low, while those not in electrical connection with the digital ground readout contact member are interpreted as being in a state of digital high.
A binary encoded signal is thus transmitted to the detection circuit of the powered injector. Assuming one code contact member/readout contact member pair is dedicated to digital ground, there are 2n-1 possible distinct binary codes that can be represented, where n is the number of code contact member/readout contact member pairs. Preferably, the detection circuit in this embodiment comprises a processing unit such as a microprocessor to read and interpret the binary encoded information. Each unique binary code preferably represents an unique syringe configuration.
In another embodiment, each of the code contact members is preferably in electrical connection with a corresponding electrical impedance element. The resistance, capacitance, inductance, or voltage of each of the elements is preferably readable by the detection circuit to provide information to the detection circuit relevant to the syringe configuration. The detection circuit may comprise, for example, a register and/or a processing unit such as a microprocessor.
In a further embodiment, the system preferably comprises at least two electrically conductive code contact members. Each of the code contact members is in electrical connection with a memory. The memory is encoded with information relevant to the syringe configuration. Upon contact and electrical connection with corresponding readout contact members, the encoded information is transmitted to a processing unit of the detection circuit.
The conductive code contact members may, for example, be positioned on the syringe to form an electrical connection with corresponding readout contact members positioned upon, for example, the injector, a pressure jacket or a heating element as described above.
In another embodiment, the system comprises an encoded element that includes at least one electrically conductive code contact member adapted to contact and make an electrical connection with the readout contact member(s). The encoded element may, for example, be incorporated in or attached to a fluid path element that is in fluid connection with the syringe, a cap attachable to the syringe (for example, on the plunger thereof) or a cap attachable to the readout element (for example, on the drive member of the injector). Such an encoded element may provide the syringe information for several successive syringes. One attachment element or cap can, for example, be provided with each box of syringes (for example, a box of 50 syringes). When a new box is opened, a new attachment element or cap with the properly encoded information is installed. Physical mating structures can be provided so that only specific syringes can fit with specific attachment elements. This embodiment can also facilitate use of different manufacturer""s syringes with various injectors. If the cap is to be mounted on the drive member, the cap may be domed so that there is no contact with the readout contact members until a syringe is engaged and pushes the cap into contact with the readout contact members. The advantage of this embodiment will be discussed below.
The conductive code contact members of the present invention are preferably shaped to substantially ensure electrical connection with the readout contact members upon operative connection of the syringe to the powered injector. In one embodiment, the conductive code contact members comprise conductive rings extending around the circumference of the body or barrel of the syringe. The code contact members may also comprise concentric conductive rings formed on a rear surface of the plunger to communicate with readout contact members positioned upon a forward surface of a drive member of the injector.
The present invention also provides an encoded element for use with a syringe and a powered injector. The injector includes or is in communication with a detector or detection circuit. The encoded element preferably comprises (i) an attachment mechanism to connect the encoded element to one of the syringe, the injector or the detector and (ii) a store of encoded syringe information readable by the detector. In one embodiment, the attachment mechanism of the encoded element is adapted to detachably connect the attachment element to one of the syringe, the injector or the detector.
The present invention also provides a syringe for use with a powered injector. The syringe comprises at least one code contact member as described above. The powered injector preferably includes a drive member, at least one electrically conductive readout contact member and is in communicative connection with a detector or a detection circuit in electrical connection with the readout contact members.
In the above embodiments, the present invention provides encoding of information that improves reliability of code recognition while maintaining low complexity and low cost relative to other syringe components. When electrical connection is made between the plunger and the drive member, the present invention has the added benefit of allowing the injector to sense when the plunger and drive member have made contact. In the case of pre-filled syringes in which the plunger can be located anywhere along the barrel, this xe2x80x9cautomatic docking detectionxe2x80x9d feature simplifies the act of connecting and then stopping the motion of the injector drive member and the syringe plunger without operator intervention.
According to another aspect of the present invention, a syringe for use with a powered injector includes an elongated body, a plunger slidably disposed within the elongated body, and an electronic storage system adapted to convey information relevant to the configuration of the syringe to a detection circuit of the powered injector without connective contact between the electronic storage medium and the detection circuit.
In this aspect of the present invention, energy is transmitted between the electronic storage system and the detection circuit without connective electrical contact therebetween. This energy provides the information relevant to the configuration of the syringe to the detection circuit. Preferably, the information is transmitted from the electronic storage system to the detection circuit via a radio frequency (RF) signal. The electronic storage system preferably includes a transponder in communicative connection with a memory. The detection circuit preferably comprises a transmitter and a receiver. The transmitter transmits an RF signal to the transponder which responds by transmitting an RF signal to the receiver. The RF signal transmitted by the transponder contains the information relevant to the configuration of the syringe. Frequencies above and expecially below the RF range may be used if the geometry and information transfer rate permit it.